This invention relates to means for recording video information and in particular to apparatus employing laser machining of holes in a film for such purpose.
Recently, a new class of apparatus has been proposed for recording and displaying optical information. Such systems rely upon the use of laser light to remove portions of a metallic film selectively and thereby create a desired pictorial representation. In one example (see U.S. Pat. No. 3,720,784), the output of a gas laser is transformed into a beam of amplitude-modulated pulses of coherent radiation by means of an acousto-optic modulator. The modulator is driven by amplitude-modulated pulses constituting a facsimile signal representing the pictorial image. The optical pulses thus produced are directed to a metal film to machine a two-dimensional array of discrete holes therein representing the original optical information. Line scan of the film is achieved by a deflecting mirror mounted on a galvanometer and vertical scan by moving the film in a direction transverse to the direction of the line scan.
The above-described system offers an attractive possibility for facsimile printing in a wide variety of applications. However, several problems are presented by this approach, such as expensive optical modulators, poor laser efficiency, complexity of the optical and electronic systems, and physical size of the printer package. The first two mentioned problems can be solved by substituting a GaAs laser for the gas laser. However, the design of such a system in a way which would reduce its complexity and size while maintaining adequate optical efficiency remains a problem.
It is therefore a primary object of the invention to provide a facsimile printer composed of micro-optical components including a solid state laser which utilizes a simple and inexpensive optical system.